Drop-bottom container



Nov. 23, 1965 D. G. cox ETAL DROP-BOTTOM CONTAINER 3 Sheets-Sheet 1 Filed Oct. 10, 1962 Mn 3 s e 4!", m mzw TXAJ? W 3 ma mam 1, 4e 2 d MMMA M aum Y 2 m 2 Nov. 23, 1965 D. G. cox ETAL 3,219,381

DROP-BOTTOM CONTAINER Filed Oct. 10, 1962 3 Sheets-Sheet 2 INVENTORJ'. 00mm 6. cax amen 4. [aw/was, Ia mew mwz United States Patent C) 3,219,381 DROP-BOTTOM CONTAINER Donald Glen Cox, Indianapolis, George A. Edwards, Jr., Greenwood, and Marvin Hausz and Charles L. Turner, Indianapolis, Ind., assignors to Gemco Manufacturing Corporation, Indianapolis, Ind., a corporation of Indiana Filed Oct. 10, 1962, Ser. No. 229,594 Claims. (Cl. 29469) This invention relates generally to containers for bulk materials and more particularly to a container having a bottom door which may be opened when the container is suspended as, for example, from an overhead crane, to discharge the contents of the container.

Heretofore, a number of types of containers have been devised for handling bulk materials such as coal, coke, limestone, ore and alloying materials. Some of these containers have been provided with a door in the bottom to facilitate discharge of the contents without the necessity of upsetting or tipping the container. However, there are several disadvantages to the containers heretofore available. One disadvantage of some is that they are made of combinations of non-standard metal shapes. Consequently, a premium is paid by the manufacturer for his materials, and assembly is more difficult than is desired. Also, the ability to supply containers in a variety of sizes and configurations is severely limited where the construction of the container invloves the use of non-standard structural sections.

Another disadvantage of some containers is the fact that during the transportation of the container and its load by means of truck, railway and other carrier, essentially the entire load of the container is carried by the door latching mechanism. This means that the mechanism is subjected to severe pounding as the vehicle carrying the container traverses bumps in the surface over which it is traveling. Accordingly, even where bearings and other parts of the latching mechanism are made of the highest quality materials, they can eventually become damaged and thus interfere with the satisfactory operation of the latching mechanism.

Another disadvantage of some containers is the fact that if a rivet or a weld breaks at some location due to a hard jolt or due to dropping the container, the container can be rendered incapable of adequately discharging the contents thereof. Another disadvantage of some containers is the fact that the door releasing actuator is inaccessible or difficult to operate if accessible. Also, in some instances, the latching mechanism is unduly complicated, expensive and susceptible to damage from accumulation of dust of various types.

It is, therefore, a general object of the present invention to provide an improved drop-bottom container.

A further object is to provide a container susceptible to low-cost manufacture in a variety of sizes and shapes.

A further object is to provide a container wherein means are provided to avoid damage to the latching mechanism during over-the-road transportation of the container.

A further object is to provide a container which is not easily damaged by rough handling.

A further object is to provide a container in which the door cannot be unlatched or opened so long as the container is not suspended.

Described briefly, a typical embodiment of the present invention includes a generally cubical body having side and end walls with portions of the walls converging downwardly and the lower margin thereof defining a discharge opening. A door extends across the opening and is hinged whereby it may be opened by dropping the unhinged side of the door. The door is mounted to the container in such a manner that the entire container and load is supported by the door when the container is resting or set to rest on some supporting surface such as the ground or a truck trailer, railroad car bottom or floor.

The latching mechanism is composed of two principal parts; namely, a latching member and a locking member. The latching member is pivotally mounted to move in a vertical plane for engaging and releasing the swinging end of the door. The locking member is pivotally mounted for action in a horizontal plane to hold said latching member in a door retaining position and alternatively in a door releasing position. A cable is secured to the locking member and is connected to an actuator ring. The ring is disposed in and engages a conically shaped socket in the exterior of the container whenever the locking member is holding the latching member in the door retaining position. The door may then be opened whenever the container is suspended from above, by simply pulling the ring.

The full nature of the invention will be understood from the accompanying drawings and the following description and the claims.

FIG. 1 is a side elevation of a typical embodiment, with a portion broken away to show interior details.

FIG. 2 is a top plan view.

FIG. 3 is a section taken along line 3-3 in FIG. 2.

FIG. 4 is a perspective of the door of the container, viewed from above.

FIG. 5 is a section through the latching mechanism taken along line 55 in FIG. 1.

FIG. 6 is a top view of the latching mechanism taken along the line 6-6 in FIG. 5.

Referring to the drawings (FIGS. 1 and 2), the container includes upstanding side walls 11 and 12 and end walls 13 and 14. Sloping side walls 16 and 17 are welded to the lower marginal edges of the side walls 11 and 12. Sloping end walls 18 and 19 are welded to the lower marginal edges of the upstanding end walls 13 and 14 respectively. Each of the sloping walls is welded along its lateral edges to one of the other sloping walls and they form a hopper designated generally by reference numeral 21. The lower marginal edges of the sloping walls define a discharge opening 22 at the bottom of the hopper. The fact that the sloping walls are planar and smooth over their entire entirety prevents any interference with discharge of the entire contents of the container whenever the door is opened as will be described.

The adjacent upstanding walls are joined along their vertical marginal edges and angle sections 23 are welded to and extend the entire length of the upstanding walls of the container at the corners. Angle sections 24 may be provided along the top marginal edges of the upstanding walls to provide a frame, and horizontal gussets or angle strips 26 may be connected across the corners if desired for rigidity. A sturdy hook 27 is provided at each of the four upper corners whereby the container may be suspended by a suitable arrangement of chains or cables (and/ or center hooks with bar from side to side to reduce height) from an overhead craneway, yard crane or other device adapted to suspension of loads. The outer marginal edge 28 of the hooked portion of the hook is inset with respect to the outer margins of the container to facilitate stacking of the containers if desired.

It should be understood, of course, that other means for the suspension of the container may be devised. For example, if the container is made in a fairly small size, and of a ferromagnetic material such as steel, the container can be lifted and carried by an electromagnet. If desired, a plate can be provided across the top of the container to further advance this purpose, particularly in larger containers.

Horizontal angle sections 31 along the sides of the container and angle sections 32 along the ends provide a frame for the junction of the upper marginal edges of the sloping walls with the lower marginal edges of the up-. standing walls. A second group of angle sections includ ing sections 33 along the side sloping walls and sections 34 along the end sloping walls form a second frame which extends around the sloping walls at a location between the upper edges of these walls and the lower marginal edges thereof. A pair of upstanding gussets 36 is provided for additional support of each of three of the sloping walls 16, 18 and 19. Five pairs of notched upstanding gussets 37 are provided along the sloping wall 17 with the notches 38 therein receiving and supporting the angle section 33 extending along the wall 17. Resilient bumper blocks 39 are supported on plates 41 welded between each pair of gussets 37. The gussets 37 have apertures 42 therein to receive hinge pins to support the door, as will become apparent.

As seen in FIG. 3 and FIG. 4, the door 43 comprises a channel section 44 along the swinging end thereof to which is welded to one end of each of five parallel channel sections 46 which provide the principal support for the door cover sheet 47. The height of the channel sections 46 forming the rib members of the door is less than the height of the channel section 44. Side plates 48 are secured to each of the outermost rib members 46 and extend the full height of the door which is, of course, the height of the channel section 44. The rib members have apertures 49 therein as do the plates 48 to receive the hinge pins 50. In this manner, the door is hinged to the gussets 37 whereby the door may swing downwardly on the hinge.

Each of the rib members extends a substantial distance from the hinge pin in a direction opposite the swinging end of the door to the rear end 46a. The extension 51 which is thereby provided can swing upwardly as the free end of the door swings downwardly whereupon the upper face 52 of the extension of each of the rib members can engage a bumper 39 supported by the gussets 37. It is desirable that the bumpers be disposed at a location such that when they are met by and stop the rib member extensions, the door will be disposed at an angle with respect to the rest of the container such that subsequent lowering of the container to rest on the ground will cause contact of the door free end with the ground and be effective to close the door without unduly tipping the container.

It will be observed from the drawings, FIG. 3. in particular, that when the door is closed, the discharge opening of the hopper is disposed slightly below the upper edge of the channel section 44 and side plates 48 and adjacent thereto. An angle section 53 is provided along the top edge of the rib members and meets the edge of the door cover sheet 47. The angle section, extending level with the top edge of the side plates completes the framing of the discharge opening with a slight well in the door and prevents any significant escape of even the finest bulk materials which may be contained in the container, and yet avoids the necessity of an elastic seal of some description.

The height of the door, the elevation of the lower frame or angle sections 33 and 34, and the location of the hinges with respect to the gussets 37 and the door rib members 46, are such that when the door is closed, the entire container and the contents thereof are supported by the door whenever the door is resting upon'a supporting surface and the container is not being suspended, as for example, by the hooks 27. As seen in FIG. 3, the channel section 44 at the free end of the door supports the angle section 33 adjacent the sloping wall 16. The side plates 48 support the angle sections 34 along the end sloping walls and the hinge pins support the angle section 33 adjacent the sloping wall 17, the weight being transmitted to the hinge pins through the gussets 37.

A housing 56 is provided for a latching mechanism 57. The housing extends partially through the sloping wall 16 and is welded thereto to prevent entry of dust or foreign matter into the latching mechanism. The latching means includes a latching member 58 mounted through a suitable bearing to the pin 59 which is secured to the housing. The latching member can therefore pivot in a vertical plane.

As can be seen in FIGS. 5 and 6, the latching member includes a hook portion 61 having an upper face 62 which engages the lower face of the upper flange 44a of the channel section 44 at the swinging end of the door whenever the container is suspended by the hooks 27. Accordingly, when the latching member is in the position shown in the drawings, it is effective to support the door and any load thereon imposed by the contents of the container whenever the container is suspended.

A projection 63 is provided on the latching member in spaced relation above the hook portion 61 and supports a shaft 64 carrying the roller 66 by a suitable hearing. The circumferential surface 67 of the roller is disposed in engageable relationship with the upper face of the upper flange 44a of the channel section 44. Accordingly, whenever the door of the container is resting upon the ground or other such supporting surface, and supporting the container, the upper edge of the door channel section 44 is closely adjacent to or engages the roller 66 and prevents pivoting of the latching member. Accordingly, so long as the container is resting on and supported by the door, it is impossible for the latching member to be rocked to a door releasing position where the upper face 62 of the hook portion 61 no longer is disposed under the upper flange of the channel section 44 at the free end of the door.

A roller 68 is mounted through a suitable bearing to a journal 69 which is normally integral with the latching member 58 and disposed for rotation of the roller in a plane transverse to the plane of action of the latching member and about an axis 71 which intersects the pivotal axis 72 of the latching member.

A locking member 73 is mounted to the shaft 74 by suitable bearings whereby the locking member 73 can pivot in a plane normal to the plane of action of the latching member. The locking member has a first cam surface 76 thereon which engages the roller 68 to hold the latching member in a door latching position until such time as the locking member is intentionally pivoted to a position for releasing the roller 68.

A cable 77 is secured to the locking member 73 and passes around the pulley 79 to the actuator ring 81 which seats at the points 82 and 83 on the conical wall 86 of the socket 84. An aperature 87 is provided which can be of ample size and have a gentle contour and include a flared portion 89 of conical shape facing opposite the socket 84. The fact that the ring seats on the walls of the socket makes possible the provision of a large aperture 87bwhich promotes ease of operation and long life of the ca le.

A spring 91 is provided to urge the locking member 73 to the position shown where it retains the latching member in the door locking position. By pulling the cable by the use of the actuator ring 81, the locking member 73 can be pulled against the bias of the spring 91 to release the roller 68. It is generally desirable to provide a cable of such length that when the locking member is disposed in the position shown in the drawings, the ring 81 snugly engages the wall of the socket. Thereby the ring is held within the outer margin 92 of the container adjacent the socket, thus avoiding interference and possible actuation by brushing against some obstruction. Yet, the ring is held in an erect attitude in the socket so as to bereadily grasped by the hand of the operator when desired to release the latching member and open the door.

A second cam surface 93 is provided on the locking member. This surface has a sharply curved portion 93a thereon which catches the roller 68 when the locking member has been pulled to the point where the first cam surface 76 can no longer support the roller 68. If the ring 81 is pulled when the container is suspended as, for example, by the hooks 27, the weight of the door and/or contents of the container and bearing on the upper face 62 of the latching member 58, is sufiicient to pivot the latching member away from its door supporting position to the door releasing position whereupon it is caught by the portion 93a of the locking member. The locking member cannot return to its original position because of interference by roller 68 resting upon the surface 93.

It will be noted that a portion 93b of the cam surface 93 extends well to one side of a radial line 94 from the pivotal axis of the member to the junction 96 between cam surfaces 93 and 76. Accordingly, the roller 68, once received in the portion 93a of the locking member, cannot be moved away without causing some rotation of the locking members against the resistance of the spring 91. Consequently, It requires a substantial force to return the latching member to its original door latching position. It will therefore, remain in the door releasing position until intentionally returned to the door latching position.

The normal way of intentionally returning the latching mechanism to the door locking position is to lower the container with the door open and allow the free or swinging side of the door to contact the ground or other supporting surface. The container is lowered further whereupon the door begins to close with respect to the container. When the upper face of the flange 44a of the channel section 44 engages the roller 67, it begins to move the latching member back toward the door locking position as the container is further lowered. During this movement, the roller 68 rolls along the cam surface 93 and particularly the portion 93b thereof, moving the locking member against the bias of the spring. The movement of the latching member by further closure of the door continues to move the locking member 73 until the roller 68 advances beyond the junction of the cam surfaces 93 and 76 whereupon the cam surface 93 no longer is supported against the spring bias by means of the roller 68. Accordingly, the locking member 73 snaps back to the original position under the urging of the spring 91 which, of course, pulls the cable and thereby the actuator ring 81 back into the socket 84. By this time, upper face 62 of the hook portion of the latching member has moved well under the lower face of the upper flange of the channel section 44 along the free end of the door. Accordingly, when the locking member has returned as just described, it will retain the roller 68 in the position shown and accordingly lock the door closed.

From the foregoing description, it will be observed that even though the actuator ring may be pulled when the container is resting on the ground, the latching member will not be relased inasmuch as the roller 66 thereof engages the upper face of the channel section 44 at the time the container is being supported by the door. The movement of the locking member has no elfect upon the position of the latching member. Thus, there is no hazard from accidental or mischievous operation of the actuator ring so long as the container is resting upon a supporting surface.

A rectangular skirt frame 96 can be provided if desired for rigidity. Yet, since it does not support the container, it need not extend down as far as the bottom of the door. Accordingly, this construction contributes toward ease of stacking the containers.

It will be apparent from the foregoing description that the present invention accomplishes all of the objects set out hereinabove. Also, it will be appreciated that a cable or other suitable linkage can be connected from the actuator ring to the cab of the vehicle or crane for handling 6 the container whereby the door can be opened by the crane operator.

In conclusion, it might be said that the present invention provides a container which effects savings of time and labor, savings of material handling costs, elimination of intermediate steps in handling, ease and speed of operation, durability and long life, and ability to liquidate its cost in a short time.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A drop-bottom container comprising:

upstanding side and end walls;

sloping walls at the lower margins of said upstanding Walls and forming a hopper with the lower margins of said sloping walls forming a discharge opening;

a frame extending around and engaging the said sloping walls outside of the hopper between said discharge opening and the upper margins of said sloping Walls;

a door covering said discharge opening, said door including a plurality of crossmembers, a side member secured to said crossmembers across the ends of said crossmembers, and end plates secured to two of said crossmembers, said end plates and side member defining three margins of said door and engageable with the underside of said frame to support said container, and support means disposed to support the portion of said frame opposite the portion engageable by said side member, at least two of said crossmembers being hinged to said support means for the support thereof the lower margins of said door projecting below all other portions of said container when said side member engages the underside of said frame whereby the entire weight of said container and the contents thereof are normally supported through said door.

- 2. A drop bottom container comprising:

upstanding side and end walls;

sheets attached to said walls and sloping downwardly and inwardly from their location of attachment, the lower margins of said sheets defining a discharge opening;

a door closing said opening,

said door having a cover disposed across said opening and having a plurality of parallel beams supporting said cover;

a plurality of upstanding gussets secured to said walls;

hinges connecting said beams to said gussets to permit the door to be pivoted down and away from said opening, said beams extending perpendicular to the axis of said hinges and to a substantial distance away from said hinges;

abutment means disposed upwardly a substantial distance from said hinges and engageable by said beams to limit the extent of pivotal action of said door;

a latch member pivotally mounted for action in a vertical plane and including a projection extending under a portion of said door to hold the door closed when the container is suspended, and said latch including a projection extending over said portion of said door for engagement and movement by said door during closing motion of said door to reset said latch member, and said latch including a roller mounted for rotation in a plane normal to the plane of action of said latch member,

a locking member pivotally mounted for action between latch holding and latch releasing positions said action being in a plane normal to said plane of action of said latch member, and said locking member having first and second cam surfaces thereon, said first cam surface normally engaging said roller to hold said latch member in a door locking position, said second cam surface being disposed to engage and retain said roller when said latch member is in a door releasing position, and said second cam surface having a concave portion extending well to one side of a radial line from the pivotal axis of said locking member to a junction of said cam surfaces to securely hold said latch member in door releasing condition, and said second cam surface then sloping to said junction to accommodate the driving of said locking member by said roller to a roller passing position during movement of said latch member by said door during a door closing motion;

a spring biasing said locking member into a latch member holding position;

a cable connected to said locking member for pulling said locking member against the bias of said spring to a latch member releasing position;

a ring on said cable;

and a conical well in one of said walls, said well receiving said ring; said well having an aperture terminating its conical wall with an oppositely facing flare, said cable passing through said aperture.

3. A drop-bottom container comprising;

upstanding side and end walls;

sloping walls at the lower margins of said upstanding walls and forming a hopper with the lower margins of said sloping walls forming a discharge opena frame extending around said sloping walls outside of the hopper and secured to said sloping walls;

a door covering said discharge opening, said door including a plurality of crossmembers, a side member secured to said crossmembers, and end members secured to said crossmembers, said end members and side member defining three margins of said door and engageable with the underside of said frame to support said container;

support means disposed to support the portion of said frame opposite the portion engageable by said side member, at least two of said crossmembers being hinged to said support means for the support thereof, the lower margins of said door projecting below all other portions of said container when said side member engages the underside of said frame whereby the entire weight of said container and the contents thereof are normally supported through said door;

a latch member pivotally mounted to said hopper and a lock member pivotally mounted to said hopper, said latch member being engaged by said side member and moved to a door retaining position when said side member engages the underside of said frame, said lock member being mounted and biased to thereupon move to position locking the latch member in said door retaining position.

4. A drop-bottom container comprising:

upstanding side and end walls;

sloping walls at the lower margins of said upstanding walls and forming a hopper, with the lower margins of said sloping walls forming a discharge opening;

a door extending across said opening and pivotally mounted to swing away from said opening;

a latch member having door engaging portions in fixed spaced relation, said latch member being pivotally mounted in the container to pivot in a vertical plane from a door retaining position to a door releasing position, said latch member including a roller mounted on an axis normal to the pivotal axis of said latch member;

a locking member mounted to pivot in a plane transverse to said vertical plane and movable from a first position holding said latch member in said door retaining position to a second. position holding said latch member in a door releasing position, said locking member having first and second cam surfaces thereon, said first cam surface normally engaging said roller to hold said latch member in said door retaining position, said second cam surface being disposed to engage and retain said roller when said latch member is in a door releasing position, said second cam surface having a concave portion extending well to one side of a radial line from the pivotal axis of said locking member to a junction of said cam surfaces securely hold said latch member in door releasing condition, and said second cam surface then sloping to said junction to accommodate the driving of said locking member by said roller to a roller passing position during movement of said latch member by said door during a door closing motion, the lower margins of said door extending below the lower margins of all other portions of said container when said door is closed whereby the entire weight of said container and the contents thereof are normally supported through said door.

5. A drop-bottom container comprising:

upstanding side and end Walls;

sloping walls at the lower margins of said upstanding walls and forming a hopper with the lower margins of the sloping walls forming a discharge opening;

a door extending across said opening and pivotally mounted to swing away from said opening;

a latch member having door engaging portions in fixed spaced relation, said latch member being pivotally mounted in the container to pivot in a vertical plane from a door retaining position to a door releasing position;

a locking member mounted to pivot in a plane transverse to said vertical plane and movable from a first position holding said latch member in said door retaining position to a second position holding said latch member in a door releasing position;

a spring urging said locking member toward said first position;

a cable connected to said locking member for pulling said locking member against tension of said spring to move said locking member to said second position;

a generally conically shaped socket having a gently contoured aperture on the axis thereof and receiving said cable;

and a hand receiving ring on said cable providing a handle to facilitate pulling thereof, said ring rigid and sized such that the outer peripheral surface thereof seats on the wall of said socket as said locking member is returned to said first position by said spring, said ring thereby centering itself in said socket and holding said cable taut and said ring in an erect attitude when said locking member has returned to said first position.

References Cited by the Examiner UNITED STATES PATENTS 468,588 2/l892 Westover 294-69 X 865,045 9/1907 Jones 294--69 1,789,775 1/1931 Russ 292.216 X 2,697,002 12/1954 Johansson 29469 2,973,886 3/1961 Elgaard 294-69 SAMUEL F. COLEMAN, Primary Examiner.

ERNEST A- ER, Exam n r.- 

1. A DROP-BOTTOM CONTAINER COMPRISING: UPSTANDING SIDE AND SIDE WALLS; SLOPING WALLS AT THE LOWER MARGINS OF SAID UPSTANDING WALLS AND FORMING A HOPPER WITH THE LOWER MARGINS OF SAID SLOPING WALLS FORMING A DISCHARGE OPENING; A FRAME EXTENDING AROUND AND ENGAGING THE SAID SLOPING WALLS OUTSIDE THE HOPPER BETWEEN SAID DISCHARGE OPENING AND THE UPPER MARGINS OF SAID SLOPING WALLS; A DOOR COVERING SAID DISCHARGE OPENING, SAID DOOR INCLUDING A PLURALITY OF CROSSMEMBERS, A SIDE MEMBER SECURED TO SAID CROSSMEMBERS ACROSS THE ENDS OF SAID CROSSMEMBERS, AND END PLATES SECURED TO TWO OF SAID CROSSMEMBERS, SAID END PLATES AND SIDE MEMBER DEFINING THREE MARGINS OF SAID DOOR AND ENGAGEABLE WITH THE UNDERSIDE OF SAID FRAME TO SUPPORT SAID CONTAINER, AND SUPPORT MEANS DISPOSED TO SUPPORT THE PORTION OF SAID FRAME OPPOSITE THE PORTION ENGAGEABLE BY SAID SIDE MEMBER, AT LEAST TWO OF SAID CROSSMEMBERS BEING HINGED TO SAID SUPPORT MEANS FOR THE SUPPORT THEREOF THE LOWER MARGINS OF SAID DOOR PROJECTING BELOW ALL OTHER PORTIONS OF SAID CONTAINER WHEN SAID SIDE MEMBER ENGAGES THE UNDERSIDE OF SAID FRAME WHEREBY THE ENTIRE WEIGHT OF SAID CONTAINER AND THE CONTENTS THEREOF ARE NORMALLY SUPPORTED THROUGH SAID DOOR. 